EP1819952B1 - Control valve for a fluid flow circuit - Google Patents

Abstract

The valve has a rectangular controlling unit (13) with the shape of a hollow body (2) truncated at its open end in an inclined plane direction at a preset angle with respect to a rotational axis for forming a lateral opening. The opening permits to control the progression of fluid flow via a lateral opening (6) of the body placed with respect to the open end. The body has a set of lateral openings connected with respective branches. An independent claim is also included for a system for cooling heat engine of a motor vehicle including a control valve.

Description

The invention relates to a control valve for a fluid circulation circuit, as well as circuits equipped with such a valve.

It is more particularly intended to provide a control valve for a cooling circuit of a motor vehicle engine.

Such a cooling circuit is traversed by a cooling fluid, usually water added with antifreeze, which circulates in closed circuit under the action of a circulation pump.

Generally, the cooling circuit comprises several branches, including a branch which contains a cooling radiator, a branch which constitutes a bypass of the cooling radiator and a branch which contains a radiator, also called "heater", for heating the radiator. cockpit.

Such a cooling circuit uses, in a conventional manner, a thermostat or a thermostatic valve which comprises a fluid inlet connected to the output of the engine and two fluid outlets which correspond, respectively, to the branch containing the cooling radiator and to the Branch forming branch.

When cold starting the engine, and as long as the coolant temperature does not reach a certain threshold, the valve circulates the coolant in the bypass branch, shorting the cooling radiator. As soon as the temperature of the cooling fluid reaches or exceeds the above threshold, the fluid cooling system passes through the radiator and bypasses the branch branch.

Generally, the cooling fluid circulates continuously in the branch that contains the heater, the heating of the passenger compartment being then obtained by mixing a cold air flow and a hot air flow that has swept this heater.

However, the distribution of the inlet and outlet ducts on the valve body leads to cumbersome implementations and a driving torque of the important adjustment member.

The perimeter of the adjustment member depends on the diameter of the outlet pipes, the number of sequences used and the travel required for the progressive opening or closing of the outlet ports by the adjustment member.

The control valve includes a body that is provided with at least one fluid inlet and at least two fluid outlets. The body of the valve is delimited in its interior by a bottom wall and a cylindrical wall arranged perpendicularly to one another and encloses a clean adjustment member to rotate about the longitudinal axis of the cylindrical wall and to take different angular positions to control the distribution of the fluid through the different valve outlets.

In order to reduce the space requirement and to reduce the drive torque of the regulating member, one solution consists of opening the fluid inlet through the bottom wall of the valve body and opening the fluid outlets at the end of the valve body. through the cylindrical wall. The adjusting member comprises a shaped part for controlling the fluid outlets with a defined law as a function of the angular position of the regulating member in the valve body.

According to embodiments of a first type, the adjustment member has the shape of a cylindrical solid body comprising at its end facing the fluid inlet a planar face which forms with the axis of rotation an angle of 45 ° to divert the flow of the inlet liquid in the side outlets depending on the angle of rotation of the adjustment member. In addition to the fact that the regulator has a large inertia, this type of embodiment induces a pressure drop in the cooling circuit, which in some applications adversely affects the proper functioning of the cooling fluid temperature control system.

To reduce the inertia of the adjustment member, it is known to conform the adjustment member in the form of a hollow cylindrical body traversed by lateral orifices allowing the distribution of the incoming fluid in the direction of the axis of rotation, in the radial outlet ports of the valve body. However, similarly to the previous embodiments, the pressure drops remain significant and the progressivity of the fluid flow required to obtain good control at very low flow rate is not ensured.

Document is known FR2827357 a valve according to the preamble of claim 1.

The invention aims to improve this situation.

It proposes for this purpose a control valve for a fluid circulation circuit which, in a preferred embodiment of the invention, constitutes a cooling circuit of a motor vehicle engine.

In this particular application, the object of the invention is to provide a valve which makes it possible to independently manage the flow rate of cooling fluid in the various branches of the engine cooling circuit, in order to optimize the temperature of the engine and the heating of the passenger compartment. The invention thus relates more particularly to a control valve for a fluid circulation circuit, comprising a body which delimits a cylindrical housing for a body of fluid. own setting to rotate about an axis of rotation and to take different angular positions to control the distribution of the fluid through orifices of the valve body.

According to a general characteristic of the invention, the adjusting member is in the form of a hollow cylindrical body open at at least one of its two ends and truncated at an open end in a plane inclined direction of an angle. (α) determined with respect to the axis of rotation, to form with a lateral opening placed at this end and intersected by said plane, a lateral opening zone for controlling the progressivity of the flow of fluid through to less an opening of the valve body located opposite this end and the adjusting member comprises a cylindrical side wall held around a hub via a transverse connecting wall sharing the inside of the body of the adjustment in two cavities, a lower cavity communicating an inlet manifold with a first outlet pipe of the valve and an upper cavity placing in communication two other outlet pipes and the valve, said cavities communicating with each other through an opening in the transverse connecting wall.

More particularly, the valve body comprises a bottom wall provided with an axial opening and a cylindrical side wall surrounding the regulating member and provided with at least two lateral openings at axial heights and at selected angular positions with respect to the axis of rotation. Advantageously, the opening located opposite the truncated end of the adjustment member is given a polygonal shape of rectangular or square type, for example, which makes it possible to obtain a progressivity of the flow of fluid at the beginning of very low opening and facilitates the thermal regulation of the cooling circuit.

According to a preferred embodiment, the lower cavity is open and has a lateral opening intersected by said inclined plane to form at the open end of the lower cavity said lateral opening zone which allows, together with the opening of the valve body opposite, to control the progressive flow of the cooling fluid in the opening of the valve body.

The transverse connecting wall has at least one lateral opening for communicating the lower cavity with the upper cavity, and the upper cavity has at least one lateral opening for communicating at least one lateral orifice of the valve body, with which it cooperates with the lower cavity through the opening in the transverse connecting wall.

According to another particular characteristic, the opening formed in the transverse connecting wall is in the form of a circular sector whose apex is located on the axis of the hub.

To limit the pressure losses, the transverse connecting partition is reinforced by a spherical or parabolic fillet connecting the transverse partition to the side wall of the first cavity.

According to another aspect, the invention relates to a fluid circulation circuit, which comprises a control valve as defined above.

In a preferred application, the circuit is made in the form of a cooling circuit of a motor vehicle engine traversed by a cooling fluid under the action of a circulation pump. In this application, the control valve is a three-way valve whose body comprises an axial opening connected to a cooling fluid inlet from the engine and three lateral fluid outlet openings connected respectively to a first branch which contains a cooling radiator, a second branch which constitutes a bypass of the cooling radiator and a third branch that contains a heater for heating the cabin.

According to a second variant embodiment, the control valve supplies the engine with cooling fluid through its axial opening, and the lateral opening of the body cooperating with the lower cavity of the adjustment member is connected to the outlet of the radiator fluid. . The two lateral openings of the remaining body are respectively connected to a second branch which constitutes a bypass of the cooling radiator and a third branch which contains a heater for heating the passenger compartment.

• les Figures 1 et 2 sont des vues de dessus et de face d'une vanne à trois voies, selon une première forme de réalisation de l'invention ;
• la Figure 3 est une vue en perspective d'un organe de réglage selon l'invention ;
• la Figure 4 est une vue en coupe d'une vanne selon un deuxième mode de réalisation de l'invention ;
• la Figure 5 est un diagramme de définition du domaine d'excursion ;
• la Figure 6 est un graphe de comparaison entre une forme d'ouverture circulaire et une forme d'ouverture carrée de même surface ;
• la Figure 7 est une vue développée de l'organe de réglage ;
• la Figure 8 est un graphe de comparaison entre deux courbes représentant des exemples de progressivité de section d'ouverture du fluide de refroidissement dans une ouverture de forme circulaire et une ouverture de forme rectangulaire en fonction de l'angle,de rotation de l'organe de réglage ;
• les Figures 9 et 10 sont deux exemples d'application d'une vanne selon l'invention aux circuits de refroidissement de moteurs thermiques de véhicules automobiles.

In the description which follows, made only by way of example, reference is made to the appended drawings, in which:

• the Figures 1 and 2 are top and front views of a three-way valve, according to a first embodiment of the invention;
• the Figure 3 is a perspective view of an adjusting member according to the invention;
• the Figure 4 is a sectional view of a valve according to a second embodiment of the invention;
• the Figure 5 is a definition chart of the field of excursion;
• the Figure 6 is a comparison graph between a circular opening shape and a square opening shape of the same surface;
• the Figure 7 is a developed view of the adjustment member;
• the Figure 8 is a comparison graph between two curves representing examples of progressivity of opening section of the cooling fluid in an opening of circular shape and an opening of rectangular shape depending on the angle of rotation of the adjustment member;
• the Figures 9 and 10 are two examples of application of a valve according to the invention to the thermal motor cooling circuits of motor vehicles.

We first refer to Figures 1 and 2 which show a control valve 1 according to a first embodiment of the invention. This control valve comprises a cylindrical body 2 limited by a bottom wall 3 provided with an axial opening 4 and a cylindrical side wall 5 of longitudinal axis XX 'having lateral openings 6, 7 and 8. In the axial opening 4 opens a tubing 9 fluid inlet. In the lateral openings 6, 7 and 8 respectively open three fluid outlet pipes 10, 11 and 12. These three outlet pipes open at axial heights and at selected angular positions with respect to the axis of rotation XX '.

Inside the valve body 2, there is housed a regulating member 13, also called a rotating member, which is designed as a hollow body optionally covered with a segment or gasket 14. The diameter of the cylindrical element substantially corresponds to the internal diameter of the valve body 2. The regulating member 13 comprises a cylindrical wall 15 fixed around a hub 16 by means of a transverse connecting wall 17. The hub 16 can to be molded or fitted along a drive rod 18 of longitudinal axis coincident with the axis XX ', one end of the hub 16 being placed in abutment against a shoulder 19 of the drive rod 18. An end of the drive rod 18 passes through a cover 20 which is fixed on a flange 21 of the valve body 2. The drive rod 18 is kept free to rotate about the axis XX 'by a bearing 22 fixed on the lid 20 and is driven in rotatio n by motorization means 23 coupled to the end of the driving rod 18 passing through the cover 20. This motorization means may be constituted, for example, by a DC brushless motor, also known by the abbreviation BLDC "brushless direct current", possibly controlled by a microprocessor capable of bringing the adjustment member 13 into a multiplicity of different positions.

In the embodiment of the Figure 2 , the end of the driving rod 18, opposite that which passes through the cover 20, extends outside the hub 16 to be optionally held by a bearing, not shown, integral with the bottom 3 of the valve body 2 However, the addition of an additional bearing is justified only for large forces capable of causing deformation of the adjusting member and consequently to impair its proper operation. For efforts that do not entail any risk of deformation of the adjusting member, an extension of the driving rod 18 out of the hub 16 is not necessary, which simplifies the embodiment of the Figure 2 and makes it possible to reduce the length of the hub 16, as shown by the example of the Figure 4 where the elements homologous to those of the Figure 2 bear the same references.

According to an essential characteristic of the invention, the transverse connecting wall 17 divides the interior of the regulating member 13 into two cavities 24, 25, a lower cavity 24 placing the inlet manifold 9 in communication with the first tubing outlet 10 of the valve and an upper cavity 25 communicating the two other outlet pipes 7 and 8 of the valve. The terms "upper" and "lower" are used herein for convenience and do not intend to limit the invention to a particular arrangement of cavities in space.

As shown in Figure 3 , the two cavities 24, 25 communicate with each other through an opening 26 of the wall transverse 17 in the form of circular sector whose apex is located on the axis of the hub 16. The lower cavity 24 has a lateral opening 27 truncated in a plane direction inclined at an angle α with respect to the longitudinal axis XX ' .

This truncated opening 27 communicates the fluid inlet tubing 9 with the lower outlet channel 10 via the lower cavity when the truncated opening 27 is positioned wholly or partly in front of the lower fluid outlet. 10. It allows, together with the lateral opening 6 of the valve body 2 with which it cooperates, to control the progressiveness of the flow of the cooling fluid in the lateral opening 6. On the Figure 3 and on the developed representation of the adjustment member 13 of the Figure 7 , the edges 27a and 27b of the truncated opening 27 extend in the upper part of the adjusting member 13 located above the transverse wall 17 and form an opening limited by a straight edge 28 oriented along a generatrix of the wall and cylindrical and an opposite edge 29 whose crenellated profile depends on the type of distribution chosen fluid in the outlet orifices, depending on the rotation angle of the adjustment member.

The cylindrical wall of the upper cavity 25 is also traversed by an opening 30 of optionally rectangular shape and has a crenellated upper edge 31 whose positions and dimensions are determined to allow the fluid passing through the upper cavity 25 to enter the outlet openings 7,8 of the valve in determined angular positions of the adjusting member.

Naturally the embodiment of the Figures 3 and 7 is not unique and it is conceivable that the number, the position and the dimensions of the openings are to be determined in each application according to the position of the openings on the valve body and sequencing retained to dispense the fluid through the outlets.

In order to improve the fluid flow towards the lower channel, the lower face of the transverse connecting wall 17 which is directly opposite the axial opening 4, is reinforced by a leave 32 of spherical or parabolic shape connecting it to the cylindrical wall of the adjustment member, which allows to better concentrate the flow of the cooling fluid to this outlet and reduce the pressure losses.

The developed perimeter of the regulating member 13 is determined as a function of the number and dimensions of the outlet pipes 10, 11, 12, the opening and closing sequences of the distributed members and the excursion Pr between two states. opening or closing of the outlets.

The Figure 5 shows the excursion Pr to run through the setting member from an initial position P1, for which the exit opening 6 is fully open, to end in a final position P2, for which the exit 6 is completely closed. In the space Pr included between these two positions, the radiator outlet opening is neither completely open nor completely closed, and this space can be used to regulate the circulation of the cooling fluid in the radiator.

In order to optimize the diameter of the regulating member 13 and to reduce it to a minimum dimension, the outlet openings 6, 7, 8 are given a square or rectangle-shaped section instead of a circular shape, which makes it possible, on equal surfaces of the openings, to reduce the developed length of the adjusting member 13 and consequently its diameter, as shown in the diagram of the Figure 6 . For a square-shaped opening of side length a and surface a ² , compared to an identical surface of a circular opening of diameter D and of area π.D ^2/4, the length a of the square relative to that of the diameter D is equal to 0,88xD. By arranging the squares formed by the exit openings so that two of their parallel sides are parallel to the axis of rotation XX ', the gain obtained is 0.12D.

Taking for example a valve composed of three branches (a radiator branch, a derivation branch and a heater branch), two regulation domains and three fixed positions, and designating at the same time by D the diameter of the radiator branch and the length of a fixed position and Pr the length of the progressivity range, the length of the regulation domain is equal to 2D + Pr and the perimeter of the segment thus obtained is P = (4 + 3) D + 2Pr. For square openings, the perimeter P becomes P = 0.88 (4 + 3) .D + 2 .P r, ie for D = 28mm a difference between the two perimeters of 21mm.

In addition, the use of a square-shaped opening allows an increase in the angle a and thus a decrease in the progressivity distance Pr.

On the Figure 6 , where it has been shown a progression of the inclined edge of angle α of the adjusting member between an angular position θ1 of the adjusting member, for which the inclined edge of the opening is tangent to the edge of the opening circular, and an angular position θ2 offset by an angle Δθ with respect to the angle θ1, for which only a portion of the opening is open, it is seen that whatever the angle α, the section progression in beginning of opening, although dependent on the angle α, remains weak. In the case of the opening in the form of a square, this progression depends much more strongly on the inclination α of the inclined edge of the adjustment member. For an angle α less than 90 °, for example, the section progression at the beginning of opening, for the same angular displacement Δθ of the adjustment member, is lower than in the case of a circular opening of the same surface because the exposed surface is less important.

A simulation result of the progression of the opening section at the beginning of opening is shown on the graph of the Figure 8 . On this graph, the curves A and B represent, as a function of the angle of rotation of the angle of the regulator, the exposed surfaces respectively of a circular opening and a square opening of the same surfaces and same angle α = 37 °. It is clearly seen that the surface progression of the curve B is much smaller than that of the curve A and that consequently the flow of the cooling fluid progresses much less at the beginning of the opening of the square-shaped opening than that of the opening of the same surface in the form of a circle, hence the possibility of passing from an angle α = 37 ° in the case of a circular opening at α = 64 ° for a square opening, making it possible to optimize geometry and reduce clutter.

We now refer to the figure 9 which shows a circuit for cooling a motor vehicle engine 34. The circuit is traversed by a cooling fluid, typically water added with antifreeze, which circulates under the action of a pump 33. The fluid, which is heated by the motor 34, leaves the latter through an outlet 35 which is connected to the axial opening 4 of the control valve 2 of the type described above. The three lateral openings 6, 7 and 8 of the body 2 are connected to three branches of the circuit. This circuit comprises a first branch which contains a cooling radiator 36 and an expansion tank 37, a second branch 38 which forms a bypass of the cooling radiator 36 and a third branch which contains a heater 39 for heating the passenger compartment of the vehicle. The opening 6 is connected to the branch containing the radiator 36, the opening 7 is connected to the branch which contains the heater 39 and the opening 8 to the branch which contains the branch branch 38.

The lateral opening 6 of the body, which cooperates with the lower cavity 24 of the adjusting member 13, is connected to the radiator branch.

The lateral openings 7 and 8 of the body 2, which cooperate with the upper cavity 25 of the adjusting member 13, are respectively connected to the second branch and the third branch.

The valve thus makes it possible to independently manage the fluid flow rates in the aforementioned branches, in order to optimize the temperature of the engine and the heating of the passenger compartment.

Note however that there is another variant to the connection of the valve in the cooling circuit of the Figure 9 and which consists, rather than connecting the axial opening 4 of the valve 1 to the outlet 35 of the motor 34, to connect it to the inlet of the radiator 36 as shown in FIG. Figure 10 . In this case, the lateral opening 6 of the body cooperating with the lower cavity 24 of the adjusting member 13 is connected to the outlet 35 of the fluid of the motor 34, the axial opening 4 of the body 2 is connected to a first branch which contains the radiator 36 and the two lateral openings 7 and 8 of the body 2 remaining are respectively connected to a second branch which constitutes a bypass of the cooling radiator 36 and a third branch which contains a heater 39 for heating the passenger compartment.

According to yet another possible variant, not shown, the connection of the valve can also be made by respectively connecting the side openings 6, 7 and 8 to the fluid outlets of the radiator 36, the branch branch 38 and the heater 39. and connecting the axial opening 4 to the fluid inlet of the motor 34.

It is also possible, in another alternative embodiment, not shown and not forming part of the invention as covered by the claims, to use a full but truncated control member to control the flow of fluid through opening of the valve body, provided that at least one of the openings has a non-circular section, for example rectangular or square, as defined above.

Claims (13)

1. Control valve (1) for a heat engine cooling circuit, comprising a body (2) that defines a cylindrical housing for an adjuster (13) that is able to rotate about an axis of rotation (XX') and adopt various angular positions for controlling the distribution of coolant through openings (4, 6, 7, 8) in the valve body (2), the adjuster (13) being produced in the form of a cylindrical body, which valve is characterized in that the adjuster (13) is produced in the form of an open hollow cylindrical body, in that the adjuster (13) is truncated at an open end on a plane inclined at an angle (α) defined with respect to the axis of rotation (XX') to form, with a side opening (27) located at this end intersected by said plane, an open side region (27) that makes it possible to modulate the flow of coolant through at least one side opening (6) of the valve body (2) situated facing this end and in that the adjuster (13) comprises a cylindrical side wall (15) held in position about a hub (16) by a transverse connecting wall (17) that divides the interior of the adjuster (13) intro two cavities, a lower cavity (24) allowing communication between an inlet tube (9) and a first outlet tube (10) of the valve and an upper cavity (25) allowing communication between two other outlet tubes (7) and (8) of the valve, said cavities communicating with each other through an opening (26) in the transverse connecting wall (17).
2. Valve according to Claim 1, characterized in that the valve body comprises an end wall (3) containing an axial opening (4) and a cylindrical side wall (5) which surrounds the adjuster (13) and which contains at least two side openings (6, 7, 8) at axial heights and in angular positions selected with respect to the axis of rotation (XX').
3. Valve according to Claim 1 or 2, characterized in that at least the opening (6) situated facing the truncated end is a square or a rectangle.
4. Valve according to one of Claims 1 to 3, characterized in that the lower cavity (24) is truncated and comprises a side opening (27) intersected by said inclined plane which makes it possible, together with a side opening (6) in the valve body with which it cooperates, to modulate the flow of coolant through this opening (6).
5. Valve according to one of Claims 1 to 4, characterized in that the upper cavity (25) comprises at least one side opening (30) for connecting at least one side opening (7, 8) of the valve body, with which it cooperates, to the lower cavity (24) through the opening (26) in the transverse connecting wall (17) .
6. Valve according to one of Claims 1 to 5, characterized in that the opening (26) in the transverse connecting wall (17) is defined by a sector of a circle whose apex is situated on the axis (XX') of the hub.
7. Valve according to one of the preceding claims, characterized in that the transverse partition (17) is reinforced by a spherical or parabolical fillet (32) connecting the transverse connecting partition (17) to the side partition of the first cavity (24).
8. Valve according to one of the preceding claims, characterized in that the control valve (1) comprises motor means (23) able to drive the adjuster (13) to selected angular positions with respect to the valve body (2).
9. Cooling circuit for a motor vehicle heat engine (34) through which a coolant is pumped by a circulating pump (33), which circuit is characterized in that it comprises a control valve (1) according to one of the preceding claims, whose body (2) comprises an axial opening (4) connected to an inlet (35) for coolant coming from the engine (34) and three fluid-outlet side openings (6, 7, 8) connected respectively to a first branch containing a cooling radiator (36), a second branch forming a bypass around the cooling radiator (36), and a third branch containing a heater core (38) for cabin heating.
10. Circuit according to the preceding claim, characterized in that the side opening (6) of the body which cooperates with the lower cavity (24) of the adjuster (13) is connected to the radiator branch.
11. Circuit according to the preceding claim, characterized in that the side openings (7, 8) of the body (2) which cooperate with the upper cavity (25) of the adjuster (13) are connected to the second and third branches, respectively.
12. Cooling circuit for a motor vehicle heat engine (34) through which a coolant is pumped by a circulating pump (33), which circuit is characterized in that it comprises a control valve (1) according to one of Claims 2 to 8, in which the side opening (6) of the body cooperating with the lower cavity of the adjuster (13) is connected to the outlet (35) of the coolant from the engine (34), the axial opening of the body (4) is connected to a first branch containing a radiator (36), and the two remaining side outlets (7, 8) of the body are connected, one to a second branch forming a bypass around the cooling radiator (36), and the other to a third branch containing a heater core (38) for cabin heating.
13. Cooling circuit for a motor vehicle heat engine (34) through which a coolant is pumped by a circulating pump (33), which circuit is characterized in that it comprises a control valve (1) according to one of Claims 2 to 8, in which the side openings (6, 7, 8) are connected respectively to the coolant outlets of the radiator (36), of the bypass branch (38), and of the heater core (39), and the axial opening (4) is connected to the coolant inlet of the engine (34).

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